From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 836DFC433F5 for ; Wed, 30 Mar 2022 17:21:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ror65cN1c2pHUkiowT63qYtuDhYKqj64xzP6vmkaKTw=; b=0LeMYXs6LTWmcH DwHagGWW7ek6YOOzsyvF/jVFwETCCoC4gBg9SwLXhMgeI9jjBXHTyKDLFkCUMUozSyxlbc4PMbmFK 1211Y3ftNnVnTq0CXW2wvpuoZfJUOLuKLfnkn0vL3qsk/3ltfbzA42W2FwlHgPjY5b+80RKb2i9In qR6W52jlh4+74lY+D7CTuPdPcweVrIeNTMfvfa3koX28D+OQY7hs2O60EPdW/R3gxT9WVKfN0GWCu ShK54Siq/nUM3u3inUb5rrd3bJ9MU1/jxcmZ3/NQ49aSpHmTt8x+1CE5aBDFvYv890TwJIl4Dng6r sFWGsC0y9hm9DTYXgv9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZbyz-00GwqJ-VA; Wed, 30 Mar 2022 17:19:46 +0000 Received: from muru.com ([72.249.23.125]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZbyv-00Gwp6-QX for linux-arm-kernel@lists.infradead.org; Wed, 30 Mar 2022 17:19:43 +0000 Received: from localhost (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 7C50780FA; Wed, 30 Mar 2022 17:17:31 +0000 (UTC) Date: Wed, 30 Mar 2022 20:19:37 +0300 From: Tony Lindgren To: Jason Gunthorpe Cc: Lu Baolu , Joerg Roedel , Christoph Hellwig , Ben Skeggs , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Alex Williamson , Eric Auger , Liu Yi L , Jacob jun Pan , David Airlie , Daniel Vetter , Thierry Reding , Jonathan Hunter , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Christoph Hellwig , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, regressions@lists.linux.dev Subject: Re: [PATCH v4 8/9] iommu: Remove unused argument in is_attach_deferred Message-ID: References: <20220216025249.3459465-1-baolu.lu@linux.intel.com> <20220216025249.3459465-9-baolu.lu@linux.intel.com> <20220330142340.GA2111031@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220330142340.GA2111031@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220330_101941_946493_695335DF X-CRM114-Status: GOOD ( 21.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org * Jason Gunthorpe [220330 14:21]: > On Wed, Mar 30, 2022 at 05:00:39PM +0300, Tony Lindgren wrote: > > Hi, > > > > * Lu Baolu [700101 02:00]: > > > The is_attach_deferred iommu_ops callback is a device op. The domain > > > argument is unnecessary and never used. Remove it to make code clean. > > > > Looks like this causes a regression for at least drivers/iommu/omap-iommu.c. > > > > To me it seems the issue is there is no is_attach_deferred implemented, so > > we get a NULL pointer dereference at virtual address 00000008: > > > > __iommu_probe_device from probe_iommu_group+0x2c/0x38 > > probe_iommu_group from bus_for_each_dev+0x74/0xbc > > bus_for_each_dev from bus_iommu_probe+0x34/0x2e8 > > bus_iommu_probe from bus_set_iommu+0x80/0xc8 > > bus_set_iommu from omap_iommu_init+0x88/0xcc > > omap_iommu_init from do_one_initcall+0x44/0x24c > > > > Any ideas for a fix? > > > > It would be good to fix this quickly so we don't end up with a broken > > v5.18-rc1.. > > > > For reference, this is mainline commit 41bb23e70b50 ("iommu: Remove unused > > argument in is_attach_deferred"). > > Are you confident in the bisection? I don't see how that commit could > NULL deref.. Oops sorry you're right, the breaking commit is a different patch, it's 3f6634d997db ("iommu: Use right way to retrieve iommu_ops") instead. I must have picked the wrong commit while testing. > Can you find the code that is the NULL deref? I can debug a bit more tomorrow. Regards, Tony _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel